Rhineland-Palatinate, Germany
We discussed it with the team and we think it's fine to use an external program to rebind mouse buttons. The one exception that you didn't ask for but we have to mention to this is the scroll wheel. We won't allow the use of the scroll wheel as it would allow for an unfair advantage compared to people using normal controls.
Xbox doesn't have the crouch dash button patch yet @beatphatsun.
How cricter did demos on xbox was that he held down on analog and pressed left or right on dpad to get them. This works because of some input priority stuff that got patched in the version that all the other consoles and PC are on currently and it added the demodash bind in-game to that patch
As announced in Celestecord we will take a bit to figure out what approach we take with a huge update like this. Submissions are frozen until we decide on our curse of action and runs done now may be rejected if there's gonna be an update in the meantime. I can't share more because we don't know either but you'll see an announcement in celestecord and in the news section on src when everything is ready
As this are the speedrunning forums, I'm answering this from a speedrunner perspective: Not dying doesn't help you much at all in this game. You will die and that is fine. Being fast and knowing strats is way more important than not dying as you at least confidently move through a room instead of being scared because you might die and want to take it too safe. That can lose a lot of time. Also if you really wanna do that you would have to learn deathless strats but at that point why not just learn fast strats that can be very consistent as well even if they have a small risk. I'm not talking about copying world record level strats here of course but having a fast strat for the rooms beats playing it safe and slow without dying most often than not. Even the any% world record has some unintentional deaths
For timing you could require chapter time, make it like "Start at the Event Horizon and end when you can skip the cutscene" which is the frame when the bird starts to flap 
But the other point with the checkpoints IL is understandable
